Moment of inertia ball bat structure fitting device

ABSTRACT

A variable moment of inertia (MOI) bat fitting device that is used to measure a hitter&#39;s output at various weight distributions.

BACKGROUND OF THE INVENTION

In baseball, the act of hitting is critical to a position player's overall performance. Throughout the history of the game, the metrics by which effective hitting has been measured has varied, however, one's ability to hit the ball consistently hard has always been valued. In essence, a consistent goal of hitters has been to transfer as much energy as possible to the ball without drastically reducing the chances of making such contact. Over time the desired shape and weight of the baseball bat has been changed, and myriad turn models (e.g. 110, 271, 243, etc.) have been created to fit hitters who desire different attributes in their bats.

The different turn models, generally speaking, alter the wood volume and weight distribution of the bat, most of the time prescribing to general length-to-weight differentials. For example, a standard 110 turn model has less overall volume than the 243-turn model. To maintain the desired length-to-weight differential, the 243 is generally made from a piece of wood that is less dense; allowing for a greater volume at the same weight. If the actual weight is the same for the two turn models, then why does the 243 feel significantly heavier when used?

The difference in swing weight among the various turn models comes down to weight distribution. The greater the weight in the barrel, in comparison to the handle region, the heavier a bat feels when swung. A bat with a lighter swing weight will generally be able to be swung with a greater velocity and reach the desired impact location with the ball more quickly. Both outcomes are desirable for a hitter, so why wouldn't all bats be made to lower the swing weight?

The description of how bat profile affects a hitter's performance could be applied to both wood and non-wood bats. However, it is when considering the optimization of a hitter's swing through selection of a bat model/profile where the wood and non-wood bats diverge. Non-wood bats, generally speaking, derive their performance from the reaction of the materials used in their construction, with the ball, on impact. Many non-wood bats now are hollow-cored and made of composite materials that break down over time creating a “trampoline effect’ upon impact, allowing the ball to leave the bat at higher exit speeds. Wood bats, however, are by rule, a single-piece, solid wood construction. The density of the wood used to construct the bat can play a factor in the efficiency of the bat-ball collision, measured by the coefficient of restitution, but, if the desired actual weight is to be maintained, then how that wood is distributed throughout the bat is critical.

The concept of moment of inertia (MOI) is becoming better understood in baseball circles, but leveraging is a factor in hitter performance that has remained more of an art than science in the wood bat industry. At its core, moment of inertia is a physics term that is related to a body's resistance to angular velocity. In layman's terms, the greater the mass at the collision-end of the body, the greater resistance it will have to the force colliding with it. With non-wood bats racing to lower the MOI as much as they can (for the aforementioned performance derivation rationale), transitioning effectively into an appropriate wood bat mode is becoming more difficult for many players.

Add to that the myriad of metrics evaluating hitter performance, mostly judging a hitter's ability to hit the ball harder and faster (e.g. swing speed, exit velocity, and launch angle). Optimizing a hitter's potential power output has never been at a greater premium or more difficult for many players. Balancing that potential power output with other metrics that will provide a greater likelihood of making consistent contact with the baseball will provide the hitter with the necessary information to select a bat turn model to maximize his potential output.

The applicant is aware of the following prior art. U.S. Pat. No. 9,731,179, “Bat Customization System” issued to Thurman on Aug. 15, 2017 discloses an apparatus for engagement with the barrel of a bat that includes a cup and at least one cover. The cup is secured for securement to a distal end of the barrel of the bat. The cup defines a cavity and includes a first connector portion. The one cover has a second connector portion cooperating with the first connector portion to releasably secure the cover to the cup over the cavity.

U.S. Pat. No. 9,724,578 entitled, “Motion Sensor in a Sports Instrument” issued to Zhoa on Aug. 8, 2017 discloses a solution to enhance motion detection and recognition of moving objects associated with various sports by embedding motion sensors into sports instruments such as a tennis rackets, badminton rackets and golf clubs, that are swung in a three-dimensional space. A motion sensor device inserted and locked inside a sports instrument is configured to detect motion associated with movements associated with the sports instrument.

U.S. Pat. No. 9,731,165 entitled, “Swing Analyzing Apparatus”, issued to Nomura on Aug. 15, 2017 discloses a swing analyzing apparatus including at least an angular velocity sensor, and impact detection section, an angular velocity information calculation section, and an impact state judgement section that judges the state of impact based on the result calculated by the angular velocity information calculation section.

U.S. Pat. No. 9,737,777 entitled “Sweet spot Trainer” issued to April on Aug. 22, 2017 discloses a lightweight sweet spot trainer including a sleeve that is slipped over the barrel end of any bat. The sleeve covers the barrel over the primary contact area of the bat. The sleeve holds a force sensor placed inside it such that, when slid over the bat, the force sensor is coincident with the sweet spot of the bat. When a ball comes in contact with the sweet spot, the force sensor directly beneath it is triggered such that instantaneous feedback is given to the athlete thereby making him/her aware of accurate sweet spot contact.

U.S. Pat. No. 9,851,374 entitled, “Inertial Measurement of Sports Motion” issued to Clark on Dec. 26, 2017 discloses a system and methods of motion tracking that can be used in connection with sports motion. Such a method includes placing one or more inertial measurement units (IMUs) on at least one of a person or one or more pieces of equipment, recording motion data associated with at least one of the person or the one or more pieces of equipment, and synchronizing the recorded motion data. The method can also include analyzing the synchronized motion data in connection with a motion standard, and generating feedback based at least in part on the analyzed motion data.

THE INVENTION

There is a variable MOI bat fitting device that can be used to measure a hitter's output at various weight distributions; mimicking the weight distribution of various turn models along the swing weight spectrum. This device has the general shape of a baseball bat throughout the handle and transition regions, but has provided a span for a mass to be position in the barrel region. By positioning this mass at a fixed location within that span, this mass effectively changes the weight distribution of the bat, thereby altering its MOI.

The invention also includes in tandem, a device to gather swing output metrics. The current design is to use a bat sensor that is associated with the bat and records data of individual swings of the bat. As technology increases the options available, better options may emerge. As long as the accompanying device has the ability to accurately capture swing metrics such mass swing velocity, time to contact, approach/attack angle, etc. it is a useful addition.

The present invention is a moment of inertia ball bat structure fitting device. The device comprises a ball bat structure that has been modified in the following manner:

The ball bat structure has a near end and a distal end. The ball bat structure has a handle region near the near end and a barrel region near the distal end. The barrel region has a span for a mass to be positioned. This span has a lesser diameter shaft than the barrel of the ball bat structure. The span has a length in the range of about 5 inches to about 7 inches.

The span has a mass encirculating the shaft. The mass is adjustable for the length of the span and securable for the length of the span. The mass is capable of being secured on the shaft at any predetermined position on the shaft. The ball bat structure contains a swing output metric sensor.

In one embodiment the moment of inertia ball bat structure fitting device has an overall length of 24 to 42 inches.

In another embodiment the moment of inertia ball bat structure fitting device has a weight of 14 ounces to 42 ounces.

In another embodiment the moment of inertia ball bat structure fitting device is manufactured from wood.

In another embodiment the moment of inertia ball bat structure fitting device is manufactured from metal.

In another embodiment the moment of inertia ball bat structure fitting device wherein the metal is aluminum.

In another embodiment the moment of inertia ball bat structure fitting device wherein the metal is titanium.

In another embodiment the moment of inertia ball bat structure fitting device wherein the ball bat structure is manufactured from composites.

In another embodiment the moment of inertia ball bat structure fitting device is manufactured from plastic.

In another embodiment the moment of inertia ball bat structure fitting device wherein the plastic is crosslinked polyethylene.

In another embodiment the moment of inertia ball bat structure fitting device wherein the plastic is polypropylene.

There is a method of evaluating a person's hitting performance using a ball bat structure the method comprising: providing a ball bat structure then allowing said person to take multiple swings in a controlled environment while setting the mass at different locations on the shaft before each swing, then capturing the metric from the sensor for each swing. Then combining and evaluating the metrics to compare a moment of inertia for various ball bat structure models. “Controlled environment” for purposes of this invention means an environment in which the person conducting the fitting (person swinging the bat or another individual) can control the variables being tested. For example, the in the use of the device of this invention, there is no ball, but if the hitter wants to maximize potential power output at six inches in front of the plate, then the fitting would be done by weighting the results from that location more heavily.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows the moment of inertia ball bat structure fitting device.

FIG. 2 shows the moment of inertia ball bat structure fitting device with a swing output metric sensor.

DETAILED DESCRIPTION OF THE DRAWINGS

FIG. 1 shows the moment of inertia ball bat structure fitting device 2. The moment of inertia ball bat structure fitting device 2 has near end 4 and a distal end 6. The near end 4 of the moment of inertia ball bat structure fitting device 2 is known as the handle region 8. The distal end 6 of the moment of inertia ball bat structure fitting device 2 is known as the barrel region 10. This barrel region 10 of the distal end 6 of the moment of inertia ball bat structure fitting device 2 has a span 12. This span 12 is generally 5.5 inches to 7.5 inches long. This span 12 consists of a lesser diameter than the barrel 10 of the bat. This span 12 has an encirculating mass 16 that is secured at some point along the lesser diameter shaft 12. The mass 16 is securable so that it cannot move on the span 12 and is movable to diagnose MOI in individual players. This fitting is conducted in a controlled environment. The controlled environment is defined as one in which the person conducting the fitting can control the variables being tested. In our situation, there is no ball, but if the hitter wants to maximize potential power output at six inches in front of the plate, then the fitting would be done by considering the results from that location more heavily. Perhaps a different MOI would be more beneficial for that hitter in that location.

FIG. 2 shows the moment of inertia ball bat structure fitting device 2 with a sensor 18. The swing output metric sensor 18 is used to record metrics of the fitting. The swing output metric sensor 18 is attached to the handle region 8 or it is imbedded into the handle region 8.

It has been discovered that the utility of the invention is applied to bats of various sizes and shapes, this accommodates players of all ages and ability levels. Generally speaking, bats range from 24″ to 42″ in length with weights ranging from fourteen ounces to forty-two ounces. These lengths and weights are intended to represent the spectrum of wood bats used across all levels of play. 

What is claimed is:
 1. A moment of inertia ball bat structure fitting device, said device comprising: a ball bat structure that has been modified in the following manner: said ball bat structure having a near end and a distal end, said ball bat structure having a handle region near said near end and a barrel region near said distal end, said barrel region having a span for a mass to be positioned, said span having a lesser diameter shaft than said barrel of said ball bat structure, said span having a length in the range of about 5½ inches to about 7½ inches; said span having a mass encirculating said shaft, said mass being adjustable for said length of said span, said mass being capable of being secured on said shaft at any predetermined position on said shaft; said ball bat structure containing a swing output metric sensor.
 2. The moment of inertia ball bat structure fitting device of claim 1 wherein the overall length of said ball bat structure is 24 to 42 inches.
 3. The moment of inertia ball bat structure fitting device of claim 1 wherein the weight of said ball bat structure is 14 ounces to 42 ounces.
 4. The moment of inertia ball bat structure fitting device as claimed in claim 1 wherein the ball bat structure is manufactured from wood.
 5. The moment of inertia ball bat structure fitting device as claimed in claim 1 wherein the ball bat structure is manufactured from metal.
 6. The moment of inertia ball bat structure fitting device as claimed in claim 5 wherein the metal is aluminum.
 7. The moment of inertia ball bat structure fitting device as claimed in claim 5 wherein the metal is titanium.
 8. The moment of inertia ball bat structure fitting device as claimed in claim 1 wherein the ball bat structure is manufactured from composites.
 9. The moment of inertia ball bat structure fitting device as claimed in claim 1 wherein the ball bat structure is manufactured from plastic.
 10. The moment of inertia ball bat structure fitting device as claimed in claim 9 wherein the plastic is crosslinked polyethylene.
 11. The moment of inertia ball bat structure fitting device as claimed in claim 9 wherein the plastic is polypropylene.
 12. A method of evaluating a person's hitting performance using a ball bat structure as claimed in claim 1, said method comprising: A. providing said ball bat structure; B. allowing said person take multiple swings in a controlled environment while setting said mass at different locations on said shaft before each swing; C. capturing said metric from said sensor for each said swing; D. combining and evaluating said metrics to compare a moment of inertia for various ball bat structure models.
 13. A moment of inertia ball bat structure fitting device, said device comprising: a ball bat structure that has been modified in the following manner: said ball bat structure having a near end and a distal end, said ball bat structure having a handle region near said near end and a barrel region near said distal end, said barrel region having a span for a mass to be positioned, said span having a lesser diameter shaft than said barrel of said ball bat structure, said span having a length in the range of about 5 inches to about 7 inches; said span having a mass encirculating said shaft, said mass being adjustable for said length of said span, said mass being capable of being secured on said shaft at any predetermined position on said shaft.
 14. The moment of inertia ball bat structure fitting device of claim 13 wherein the overall length of said ball bat structure is 24 to 42 inches.
 15. The moment of inertia ball bat structure fitting device of claim 13 wherein the weight of said ball bat structure is 14 ounces to 42 ounces.
 16. The moment of inertia ball bat structure fitting device as claimed in claim 13 wherein the ball bat structure is manufactured from wood.
 17. The moment of inertia ball bat structure fitting device as claimed in claim 13 wherein the ball bat structure is manufactured from metal.
 18. The moment of inertia ball bat structure fitting device as claimed in claim 17 wherein the metal is aluminum.
 19. The moment of inertia ball bat structure fitting device as claimed in claim 17 wherein the metal is titanium.
 20. The moment of inertia ball bat structure fitting device as claimed in claim 13 wherein the ball bat structure is manufactured from composites.
 21. The moment of inertia ball bat structure fitting device as claimed in claim 13 wherein the ball bat structure is manufactured from plastic.
 22. The moment of inertia ball bat structure fitting device as claimed in claim 21 wherein the plastic is crosslinked polyethylene.
 23. The moment of inertia ball bat structure fitting device as claimed in claim 21 wherein the plastic is polypropylene. 